Drive rod and knife blade for an articulating surgical instrument

ABSTRACT

A surgical instrument includes a housing including an actuator disposed thereon and an elongated shaft extending therefrom. The elongated shaft includes an end effector assembly including a pair of opposing jaw members including a knife channel defined therein. An articulation section is disposed between the housing and the end effector assembly and is configured to articulate the end effector assembly upon actuation of the actuator, the articulating section and a proximal end of the knife channel defining a first distance therebetween. A knife assembly includes a knife having a length, the proximal end including an engagement feature disposed thereon. A knife drive rod is configured to engage the engagement feature to secure the knife drive rod to the knife such that the distal end of the knife extends beyond the engagement feature and wherein the knife length is less than the length of the first distance.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 62/825,870, filed on Mar. 29, 2019, the entirecontent of which is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates surgical instruments, and moreparticularly, to a drive rod and knife blade for use with anarticulating surgical forceps.

Background of Related Art

A surgical forceps is a pliers-like instrument that relies on mechanicalaction between its jaw members to grasp, clamp, and constrict tissue.Electrosurgical forceps utilize both mechanical clamping action andenergy to heat tissue to treat, e.g., coagulate, cauterize, or seal,tissue. Typically, once tissue is treated, the surgeon has to accuratelysever the treated tissue. Accordingly, many electrosurgical forceps aredesigned to incorporate a knife or cutting member utilized toeffectively sever the treated tissue.

Many electrosurgical forceps include various actuators to orient the jawmembers for tissue treatment. For example, many forceps includerotational wheels (or the like) disposed in proximity to a surgeon'shands to enable the surgeon to selectively rotate the jaw members asneeded during an operation. A trigger (or similar) may be disposed onthe forceps housing to allow a surgeon to selectively deploy a knife orcutting element as needed during surgery. Other actuators includearticulating mechanisms disposed in proximity to the surgeon's hands toallow the surgeon to selectively articulate (e.g., pitch and yaw) thejaw members as needed during surgery.

With particular respect to articulating forceps that include adeployable knife, one important feature of these types of forceps is theknife drive rod which typically needs to be both sufficiently flexibleto allow articulation of the jaw members while also being strong enoughto advance and retract a knife blade through tissue. Another designconsideration with articulating forceps is to minimize the distance fromthe articulation region to the jaw members commonly referred to as “deadspace”. By minimizing this distance, usability and surgical access isimproved. In other words and as mentioned above because of thearticulating joints, a flexible wire or tube is typically used toadvance and retract the knife blade. The length of the knife bladeattached to the flexible wire is a constraint for dead space, e.g., theknife should not retract behind the tissue stop of the jaw members(little or no portion of the knife blade should retract into any of thearticulation joints (unless specifically designed for a particularpurpose). However, this constraint typically dictates that additionallength must be added to the forceps to house the retracted knife bladebetween the jaw member and articulating joint, i.e., a longer knifeblade naturally means a longer distance between the jaw members and thearticulation joint and undesirable dead space.

SUMMARY

As used herein, the term “distal” refers to the portion that is beingdescribed which is further from a user, while the term “proximal” refersto the portion that is being described which is closer to a user.Further, to the extent consistent, any or all of the aspects detailedherein may be used in conjunction with any or all of the other aspectsdetailed herein.

In accordance with aspects of the present disclosure, a surgicalinstrument includes a housing having one or more actuators disposedthereon and an elongated shaft extending from a distal portion of thehousing. The elongated shaft includes an end effector assembly engagedat a distal end thereof having a pair of opposing jaw members, at leastone of the jaw members including a knife channel defined therein. Anarticulation section is disposed between the housing and the endeffector assembly and is configured to selectively articulate the endeffector assembly upon actuation of the actuator(s). The articulatingsection and a proximal end of the knife channel define a first distancetherebetween. A knife assembly includes a knife having proximal anddistal ends defining a knife length therebetween, the proximal endincluding an engagement feature disposed thereon. A knife drive rod isconfigured to operably engage the engagement feature to secure the knifedrive rod to the knife such that the distal end of the knife extendsbeyond the engagement feature and wherein the knife length is less thanthe length of the first distance.

In aspects according to the present disclosure, the engagement featureof the knife assembly includes one or more capture tabs disposed withinin an aperture defined within the proximal end of the knife. In otheraspects according to the present disclosure, the knife assemblyincludes: a tube configured to operably engage the capture tab(s)disposed within the aperture; and a knife drive rod configured tooperably engage the tube disposed within the aperture.

In aspects according to the present disclosure, a weld operably engagesthe tube to the knife. In yet other aspects according to the presentdisclosure, the knife and the tube are made from similar metals toincrease the strength of the weld. In still other aspects according tothe present disclosure, the distal end of the knife drive rod threadablyengages the tube.

In yet other aspects according to the present disclosure, the engagementfeature includes an aperture defined within the knife, the apertureconfigured to receive a bent end of the knife drive rod. In still otheraspects according to the present disclosure, the engagement feature ofthe knife includes an aperture defined in the proximal end of the knifethat includes a series of spaced apart fins extending thereacross andthe knife drive rod is configured to operably engage the fins to securethe knife drive rod to the knife. In aspects according to the presentdisclosure, the knife drive rod is configured to engage the fins in aweave-like manner from a proximal end of the aperture to a distal end ofthe aperture. In still other aspects according to the presentdisclosure, a retention mechanism is operably disposed at a distal endof the knife drive rod and is configured to secure the knife drive rodin engagement between the fins.

In aspects according to the present disclosure, the engagement featureincludes one or more detents disposed on a proximal end of the knife andthe knife drive rod includes one or more complementary apertures definedtherein configured to engage the one or more detents to secure the knifeto the knife drive rod. In other aspects according to the presentdisclosure, the one or more detents is welded within the aperture.

In accordance with aspects of the present disclosure, a surgicalinstrument includes a housing having one or more actuators disposedthereon and an elongated shaft extending from a distal portion of thehousing. The elongated shaft includes an end effector assembly engagedat a distal end thereof that includes a pair of opposing jaw members, atleast one of the jaw members including a knife channel defined therein.An articulation section is disposed between the housing and the endeffector assembly and is configured to selectively articulate the endeffector assembly upon actuation of the actuator(s). The articulatingsection and a proximal end of the knife channel define a first distancetherebetween. A knife assembly includes: a knife having proximal anddistal ends that define a knife length therebetween that is less thanthe length of the first distance; and a knife drive rod welded to theknife.

In aspects according to the present disclosure, the weld formed betweenthe knife and the knife drive rod is disposed on a proximal end of theknife. In other aspects according to the present disclosure, the weldformed between the knife and the knife drive rod is disposed along aninner surface of the knife.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present disclosure willbecome more apparent in view of the following detailed description whentaken in conjunction with the accompanying drawings wherein likereference numerals identify similar or identical elements and:

FIG. 1A is a perspective view of endoscopic surgical forcepsexemplifying the aspects and features of the present disclosure, whereinthe shaft of the endoscopic surgical forceps is disposed in anon-articulated position and wherein the jaw members of the endoscopicsurgical forceps are disposed in a spaced-apart position;

FIG. 1B is a perspective view of the endoscopic surgical forceps of FIG.1A, wherein the shaft of the endoscopic surgical forceps is disposed inan articulated position and wherein the jaw members of the endoscopicsurgical forceps are disposed in an approximated position;

FIGS. 1C and 1D are enlarged schematic views of one embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIGS. 2A and 2B are enlarged schematic views of another embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIG. 3 is an enlarged schematic view of another embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIG. 4 is an enlarged schematic view of another embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIGS. 5A and 5B are enlarged schematic views of another embodiment of anengagement feature for coupling a knife blade chip to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIG. 6 is an enlarged schematic views of another embodiment of anengagement feature for coupling a knife blade chip to a knife drive rodexemplifying the aspects and features of the present disclosure;

FIG. 7 is an enlarged schematic view of another embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure; and

FIGS. 8A and 8B are enlarged schematic views of another embodiment of anengagement feature for coupling a knife blade to a knife drive rodexemplifying the aspects and features of the present disclosure.

DETAILED DESCRIPTION

Referring generally to FIGS. 1A and 1B, an endoscopic surgical forcepsexemplifying the aspects and features of the present disclosure is showngenerally identified by reference numeral 10. For the purposes herein,endoscopic surgical forceps 10 is generally described. Aspects andfeatures of endoscopic surgical forceps 10 not germane to theunderstanding of the present disclosure are omitted to avoid obscuringthe aspects and features of the present disclosure in unnecessarydetail.

Forceps 10 includes a housing 20, a handle assembly 30, a triggerassembly 60, a rotating assembly 70, a plurality of articulationactuators 80, an activation switch 4, and an end effector assembly 100.Forceps 10 further includes a shaft 12 having a distal end 12 aconfigured to mechanically engage end effector assembly 100 and aproximal end 12 b that mechanically engages housing 20. Forceps 10 alsoincludes cable 2 that connects forceps 10 to an energy source (notshown), e.g., a generator or other suitable power source, althoughforceps 10 may alternatively be configured as a battery-powered device.Cable 2 includes a wire (or wires) (not shown) extending therethroughthat has sufficient length to extend through shaft 12 in order toprovide energy to one or both tissue-treating plates 114, 124 of jawmembers 110, 120, respectively, of end effector assembly 100. Activationswitch 4 is coupled to tissue-treating plates 114, 124 and the source ofenergy for selectively activating the supply of energy to jaw members110, 120 for treating, e.g., cauterizing, coagulating/desiccating,and/or sealing, tissue.

Shaft 12 of forceps 10 defines a distal segment 13 positioned towardsdistal end 12 a thereof, a proximal segment 14 positioned towardsproximal end 12 b thereof, and an articulating section 15 disposedbetween the distal and proximal segments 13, 14, respectively.Articulating section 15 includes a plurality of articulating links 16having a plurality of articulation cables 17 extending therethrough.Each cable 17 is operably engaged at a distal end thereof to distalsegment 13 and at a proximal end thereof to one of the articulationactuators 80 to enable articulation of distal segment 13 and, thus, endeffector assembly 100, relative to proximal segment 14 upon actuation ofone or more of articulation actuators 80. Rotating assembly 70 operablycouples shaft 12 to housing 20 to enable selective rotation of shaft 12and, thus, end effector assembly 100, relative to housing 20.

Handle assembly 30 of forceps 10 includes a fixed handle 50 and amovable handle 40. Fixed handle 50 is integrally associated with housing20 and handle 40 is movable relative to fixed handle 50. Movable handle40 of handle assembly 30 is operably coupled to a drive assembly (notshown) that, together, mechanically cooperate to impart movement of oneor both of jaw members 110, 120 of end effector assembly 100 about apivot 103 between a spaced-apart position (FIG. 1A) and an approximatedposition (FIG. 1B) to grasp tissue between jaw members 110, 120. Asshown in FIG. 1A, movable handle 40 is initially spaced-apart from fixedhandle 50 and, correspondingly, jaw members 110, 120 of end effectorassembly 100 are disposed in the spaced-apart position. Movable handle40 is compressible from this initial position to a compressed positioncorresponding to the approximated position of jaw members 110, 120 (FIG.1B).

Trigger assembly 60 includes a trigger 62 coupled to housing 20 andmovable relative thereto between an un-actuated position and an actuatedposition. Trigger 62 is operably coupled to a cutting mechanism 85,various embodiments of which are detailed below, to actuate the cuttingmechanism 85 to cut tissue grasped between jaw members 110, 120 of endeffector assembly 100 upon actuation of trigger 62. As an alternative toa pivoting trigger 62, a slide trigger, push-button, toggle switch, orother suitable actuator may be provided.

End effector assembly 100, as noted above, includes first and second jawmembers 110, 120. Each jaw member 110, 120 includes a proximal flangeportion 111, 121, an outer insulative jaw housing 112, 122 disposedabout the distal portion (not explicitly shown) of each jaw member 110,120, and a tissue-treating plate 114, 124, respectively. Proximal flangeportions 111, 121 are pivotably coupled to one another about pivot 103for moving jaw members 110, 120 between the spaced-apart andapproximated positions, although other suitable mechanisms for pivotingjaw members 110, 120 relative to one another are also contemplated. Thedistal portions (not explicitly shown) of the jaw members 110, 120 areconfigured to support jaw housings 112, 122, and tissue-treating plates114, 124, respectively, thereon.

Outer insulative jaw housings 112, 122 of jaw members 110, 120 supportand retain tissue-treating plates 114, 124 on respective jaw members110, 120 in opposed relation relative to one another. Tissue-treatingplates 114, 124 are formed from an electrically conductive material,e.g., for conducting electrical energy therebetween for treating tissue,although tissue-treating plates 114, 124 may alternatively be configuredto conduct any suitable energy, e.g., thermal, microwave, light,ultrasonic, etc., through tissue grasped therebetween for energy-basedtissue treatment. As mentioned above, tissue-treating plates 114, 124are coupled to activation switch 4 and the source of energy (not shown),e.g., via the wires (not shown) extending from cable 2 through forceps10, such that energy may be selectively supplied to tissue-treatingplate 114 and/or tissue-treating plate 124 and conducted therebetweenand through tissue disposed between jaw members 110, 120 to treattissue.

One or both of jaw members 110, 120 may further define alongitudinally-extending channel 125 (only the channel 125 of jaw member120 is shown) for allowing reciprocation of the cutting mechanism 85upon actuation of trigger 62. Actuation of the trigger 62 reciprocates aknife drive rod, e.g., knife drive rod 280 of FIG. 2B, operably coupledto the cutting mechanism, e.g., knife 285. Together and as used herein,the knife, e.g., knife 285 and knife drive rod, e.g., knife drive rod280, form a knife assembly 250. Knife drive rod 280 is made from aflexible material of sufficient strength to allow the knife drive rod280 to both push and pull the knife 285 through tissue disposed betweenjaw members 110, 120. Moreover, the flexibility of the knife drive rod280 allows the knife drive rod 280 to flex as needed during articulationof the jaw members 110, 120. The knife drive rod 280 may be made from avariety of flexible materials that exhibit the necessary strength andflexibility to allow smooth translation of the knife drive rod 280through one or more articulating joints of articulating section 15 suchas: NiTiNOL, stainless Steel or high carbon steel, Inconel, Monel,Nimonic, Nitronic, Hastelloy (Nickel based alloys other than NiTiNOL),Elgiloy (Cobalt-Nickel), Brass, Phosphor Bronze, Beryllium Copper,Chrome-Vanadium or Chrome-Silicon, Titanium, and/or Braided Cable (i.e.Steel or Tungston).

The knife drive rod 280 generally refers to a drive member that may bein the shape of a rod, cable, braided cable, tube, piece of sheet metalor plastic, screw and the like. It is envisioned that the term “rod”covers all of these and other commonly known types of drive members madefrom a variety of different materials so long as it is strong enough,durable enough and/or stiff enough to advance and retract the knife 285.

Knife 285 is typically made from a stronger, harder, stiffer, and/ormore durable material, e.g., stainless steel, to allow the knife 285 toeasily translate through tissue on a repeated basis. Other materials arealso contemplated such as: Stainless Steel or High Carbon Steel, ToolSteel, High Speed Steel, Chrome Steel, Tungston Carbide, Titanium,Vanadium Alloys, Ceramic, Glass, and/or Plastic.

Since it is often difficult to assure a consistent and strong weldbetween two dissimilar metals, i.e., utilizing a flexible firstmaterial, e.g., Nitinol, for the knife drive rod 280 with a secondstronger material for the knife 285, e.g., stainless steel, variouswelding, swaging and mechanical capture techniques are described belowwith respect to FIGS. 2A-10.

As mentioned above, because of the articulation of the shaft 12, aflexible wire or drive rod, e.g., drive rod 180 of FIG. 1D, needs to beused to push or pull a knife 185. To minimize the length of the shaft 12and the so called “dead space” (the space between the end of thearticulation section 15 and the jaw members 110, 120) the length of theknife 185 attached to the drive rod 180 should be minimized which willenhance usability and surgical access. The knife 185 still needs toretract proximally enough to clear the tissue stop (not shown) of thejaw members 110, 120 without retracting into any portion of thearticulation section 15. This ensures proper articulation and allows theforceps 10 to deploy the knife 185 with minimal friction and wear.However, this typically requires that additional length needs to beadded to the shaft 12 to house the retracted knife between the jawmembers 110, 120 and the articulating section 15. FIGS. 1C-8B showvarious retention mechanisms and methods of attaching a shorter knife185 to the knife drive rod 180.

FIGS. 1C and 1D show an embodiment of the knife 185 for engagement tothe knife drive rod 180 that minimizes dead space between thearticulating section 15 and the jaw members 110, 120. More particularly,knife 185 includes a knife body 184 having a distal end 186 and aproximal end 182, the distal end 186 including a sharpened edge forcutting tissue and the proximal end 182 including an aperture 187defined therein for capturing the knife drive rod 180. Together theknife 185 and knife drive rod 180 form a knife assembly 150. A pair ofopposing capture tabs 181 a and 181 b are etched (or otherwise formed)from the proximal end 182 into the aperture 187 and are configured tocapture and secure a tube 183 therebetween. The inner periphery of thetube 183 is configured to engage, e.g., threadably engage, the knifedrive rod 180. During assembly, the tube 183 and the knife drive rod 180may be welded, e.g., spot-welded, laser welded, inductively welded, beadwelded, etc. or crimped after engagement within the tube 183 to provideadditional engagement of the knife drive rod 180 therein.

Since the knife drive rod 180 needs to be flexible to accommodatearticulation of the jaw members 110, 120, and the knife body 184 needsto be sufficiently strong to cut through tissue on a repeated basis, theknife drive rod 180 and the knife body 184 are typically made fromdissimilar materials and any such weld or bond may be weaker thandesired. Thus, additional mechanical engagement between the twoelements, e.g., the knife drive rod 180 and knife body 184, is needed toprevent mechanical failure. Tube 183 may be made from any type of metal,e.g., stainless steel, that will provide a secure weld to knife body184. In embodiments, the knife body 184 and the tube 183 are made fromthe same material, e.g., stainless steel, to assure a good weld. Thetube 183 may also be welded to the knife 185 along the top and/or bottomlength of the tube 183.

By providing a strong mechanical connection between the knife drive rod180 and the tube 183 and a strong mechanical connection between the tube183 and the knife body 184, the chances of mechanical failure is greatlyreduced.

FIGS. 1C and 1D show the knife 185 extended beyond the attachment point.Only a necessary portion of the distal end 184 of the knife 185 projectsbeyond the connection to the knife drive rod 180 to minimize dead space.For a curved jaw design, this would ensure the attachment tube 183 anddrive rod 180 do not enter the curved portion of the jaw members, 110,120.

FIGS. 2A-2B show another embodiment of a knife 285 for engagement to aknife drive rod 280. More particularly, knife 285 includes a knife body284 having a distal end 286 and a proximal end 282, the distal end 286including a sharpened edge for cutting tissue and the proximal end 282including a slot 287 defined therein and configured to capture a tube281 crimped, threaded or welded onto a portion of the knife drive rod280. Together the knife 285 and knife drive rod 280 form a knifeassembly 250.

Since the knife drive rod 280 needs to be flexible to accommodatearticulation of the jaw members 110, 120, and the knife body 284 needsto be sufficiently strong to cut through tissue on a repeated basis, theknife drive rod 280 and the knife body 284 are typically made fromdissimilar materials and any such weld or bond may be weaker thandesired. Thus additional mechanical engagement between the two elements,e.g., the knife drive rod 280 and knife body 284, is needed to preventmechanical failure. Tube 281 may be made from any type of metal, e.g.,stainless steel, that will provide a secure weld to knife body 284.

In embodiments, the knife body 284 and the tube 281 are made from thesame material, e.g., stainless steel, to assure a good weld. Theproximal end 282 of the knife body 280 also includes an aperture 289defined therein configured to receive the distal end 283 of the knifedrive rod 280. More particularly, the distal end 283 of the knife rod280 is bent at an angle, e.g., 90°, such that during assembly the distalend 283 may be inserted into aperture 289 to secure the knife drive rod280 to the knife body 284. In addition and during assembly the tube 281is seated within slot 287 to capture the tube 281 therein and provideadditional mechanical engagement between the knife drive rod 280 and theknife body 284. Only a necessary portion of the distal end 284 of theknife 285 projects beyond the connection to the knife drive rod 280 tominimize dead space.

FIG. 3 shows another embodiment of a knife 385 for engagement to a knifedrive rod 380. More particularly, knife 385 includes a knife body 384having a distal end 386 and a proximal end 382, the distal end 386including a sharpened edge for cutting tissue and the proximal end 382configured to mechanically engage a tube 381 which may be crimped,threaded or welded onto the proximal end 382 along a lower edge 387 ofthe knife body 384. Together the knife 385 and knife drive rod (notshown) form a knife assembly (not shown). Tube 381 may be made from anytype of metal, e.g., stainless steel, that will provide a secure weld toknife body 384.

In embodiments, the knife body 384 and the tube 381 are made from thesame material, e.g., stainless steel, to assure a good weld. The knifedrive rod is secured within the tube 381 during assembly via crimping,welding, swaging or threadable engagement. Engaging the knife drive rodto the tube 381 which is secured to the lower edge 387 of the knife body384 facilitates a more balanced actuation of the knife 385 duringtranslation since the mechanical engagement of the knife body 384 andthe tube 381 is along the centerline (lower edge 387) of the knife 385.Hereagain, only a necessary portion of the distal end 384 of the knife385 projects beyond the connection to the knife drive rod to minimizedead space. In embodiments, the knife drive rod and/or the abovedescribed retention feature may provide a width or depth to the knife385 that may be utilized to facilitate retention of the knife 385 withinthe jaw members 110, 120 or channel (not shown) defined within one orboth jaw members 110, 120.

FIG. 4 shows another embodiment of a knife 485 for engagement to a knifedrive rod 480. More particularly, knife 485 includes a knife body 484having a distal end 486 and a proximal end 482, the distal end 486including a sharpened edge for cutting tissue and the proximal end 482including an aperture 487 defined therein for capturing the knife driverod 480. Together the knife 485 and knife drive rod 480 form a knifeassembly 450. A series of fins 483 are etched from the proximal end 482into the aperture 487 that include one or more recessed portions (notshown) defined therein configured to partially receive the outerperiphery of the knife drive rod 480 to mechanically capture the knifedrive rod 480 on opposing sides along the length thereof. Duringassembly, the knife drive rod 480 is weaved through the various fins 483to engage the recesses and secure the knife drive rod 480 to the knife485. Weaving the knife drive rod 480 through the fins 483 provideslateral stability to the knife 485 and knife drive rod 480 during use.Once the knife drive rod 480 is weaved through the fins 483, a retentionmechanism, e.g., a cap 481, is secured (e.g., welded, swaged, crimped,etc.) to the end of the knife drive rod 480 to lock the knife drive rod480 in place within aperture 487 of knife 485. It is envisioned that anyother type of enlarged area at the distal end can function as aretention mechanism, e.g., forged end, bubble-like end, additionalpieces welded, crimped or swaged to end, etc. The dimensions of the cap481 are sized greater than the dimensions of the recesses to preventslippage of the mechanical connection during use. The knife 485 may bemade from stainless steel, e.g., surgical stainless steel (316 SS) orother surgical metal, and the knife drive rod 480 may be made fromNitinol or other flexible metal or a metal hybrid (Nitinol inner rod andhelical hollow strand HHS outer casing). Again, only a necessary portionof the distal end 484 of the knife 485 projects beyond the connection tothe knife drive rod 480 to minimize dead space.

FIGS. 5A and 5B show another embodiment of a knife 585 for engagement toa knife drive rod 580. More particularly, knife 585 includes a knifebody 584 having a distal end 586 and a proximal end 582, the distal end586 including a sharpened edge for cutting tissue and the proximal end382 including lower edge 587 including an inner facing surfaceconfigured to engage the knife drive rod 580 via welding, or swagingalong a weld 581. Together the knife 585 and knife drive rod 580 form aknife assembly 550. Knife 585 is generally chip-like as compared to theother knives, e.g., knife 285, described herein and, in this particularembodiment, the knife 585 is welded directly to the knife drive rod 580.

Since the knife drive rod 580 needs to be flexible to accommodatearticulation of the jaw members 110, 120, and the knife body 584 needsto be sufficiently strong to cut through tissue on a repeated basis, theknife drive rod 580 and the knife body 584 are typically made fromdissimilar materials and any such weld or bond may be weaker thandesired. Thus additional mechanical engagement between the two elements,e.g., the knife drive rod 580 and knife body 584, may be needed toprevent mechanical failure. Any one of the aforementioned additionalretention features may be implemented with chip-like knife 585 toproduce a stronger engagement. On the other hand, the knife 585 and theknife drive rod 580 may be made from the same type of material, e.g.,stainless steel, that will provide a secure weld to knife body 584.

In addition and during assembly the knife drive rod 580 may be seatedwithin a recess (not shown) defined in a side of the knife 585 to atleast partially capture the knife drive rod 580 therein and provideadditional mechanical engagement between the knife drive rod 580 and theknife body 584.

FIG. 6 shows another embodiment of a knife 685 for engagement to a knifedrive rod 680. More particularly, knife 685 includes a knife body 684having a distal end 686 and a proximal end 682, the distal end 686including a sharpened edge for cutting tissue and the proximal end 682including a rear edge 687 including an inner facing surface configuredto engage the knife drive rod 680 via welding or swaging. Together theknife 685 and knife drive rod 680 form a knife assembly 650. Knife 685is generally chip-like similar to the embodiment shown in FIGS. 5A and5B, and, in this particular embodiment, the proximal or rear edge ofknife 685 is welded directly to the knife drive rod 680. In addition andduring assembly the knife drive rod 680 may be seated within a recess(not shown) defined in the proximal or rear edge of the knife 685 to atleast partially capture the knife drive rod 680 therein and provideadditional mechanical engagement between the knife drive rod 680 and theknife body 684.

Moreover, any one of the aforementioned additional retention featuresmay be implemented with chip-like knife 685 to produce a strongerengagement. On the other hand, the knife 685 and the knife drive rod 680may be made from the same type of material, e.g., stainless steel, thatwill provide a secure weld to knife body 684.

FIG. 7 shows another embodiment of a knife 785 for engagement to a knifedrive rod (not shown). More particularly, knife 785 includes a knifebody 784 having a distal end 786 and a proximal end 782, the distal end786 including a sharpened edge for cutting tissue and the proximal end782 including a series of retention tabs 783 that project generallylaterally therefrom. The retention tabs may be stamped or etched in theproximal end 782 and are configured to capture and secure the knifedrive rod. During assembly, the knife drive rod and the retention tabs783 may be welded, e.g., spot-welded, laser welded, or crimped afterengagement to provide additional engagement of the knife drive rod tothe knife 785.

Since the knife drive rod needs to be flexible to accommodatearticulation of the jaw members 110, 120, and the knife body 784 needsto be sufficiently strong to cut through tissue on a repeated basis, theknife drive rod and the knife body 784 are typically made fromdissimilar materials and any such weld or bond may be weaker thandesired. Thus additional mechanical engagement between the two elements,e.g., the knife drive rod and knife body 784, may be needed to preventmechanical failure. Retention tabs 783 may be made from any type ofmetal that will provide a secure weld to knife drive rod. Inembodiments, the knife body 784 and the knife drive rod are made fromthe same material, e.g., stainless steel, to assure a good weld. Byproviding a strong mechanical connection between the knife drive rod andthe retention tabs 783, the chances of mechanical failure is greatlyreduced.

Alternatively, the retention tabs 783 may be utilized to retain theknife 785 within a knife channel (not shown) defined within one or bothjaw members 110, 120. In this instance, the knife 785 would be attachedor otherwise engaged to the knife drive rod 780 by way of one or more ofthe retention features or retention methods described herein. Inembodiments, the knife drive rod 780 and/or any of the above describedretention features may provide a width to the knife 785 that may beutilized to facilitate retention of the knife 785 within the jaw members110, 120 or channel (not shown) defined within one or both jaw members110, 120.

FIGS. 8A and 8B show another embodiment of a knife 885 for engagement toa knife drive rod 880. More particularly, knife 885 includes a knifebody 884 having a distal end 886 and a proximal end 882, the distal end886 including a sharpened edge for cutting tissue and the proximal end882 including one or more detents 883 a, 883 b projecting therefromconfigured to capture the knife drive rod 880. More particularly, theknife drive rod 880 includes a corresponding one or more apertures 889a, 889 b defined therein and configured to operably engage the detents883 a, 883 b upon assembly. Once engaged, the knife drive rod 880 may bewelded, riveted, or swaged to the knife 885. Alternatively or inaddition to, the detents 883 a, 883 b may be spot-welded within theapertures 889 a, 889 b to further secure the knife drive rod 880 to theknife 885.

The detents 883 a, 883 b of the knife 885 and the knife drive rod 880may be made from any type of metal that will provide a secure weld.Since a majority of the extension and retraction forces associated withtranslating the knife 885 will be offloaded by the mechanical engagementof the detents 883 a, 883 b and apertures 889 a, 889 b, the additionalweld would not necessarily need to be strong (unlike some of theaforedescribed embodiments). As such, the knife 885 and the knife driverod 880 do not necessarily need to be made from the same type ofmaterial to insure a secure weld. Thus, a flexible super elasticmaterial, e.g., Nitinol, may be used for the knife drive rod 880 andstainless steel may be utilized for the knife 885.

The various embodiments disclosed herein may also be configured to workwith robotic surgical systems and what is commonly referred to as“Telesurgery.” Such systems employ various robotic elements to assistthe clinician and allow remote operation (or partial remote operation)of surgical instrumentation. Various robotic arms, gears, cams, pulleys,electric and mechanical motors, etc. may be employed for this purposeand may be designed with a robotic surgical system to assist theclinician during the course of an operation or treatment. Such roboticsystems may include remotely steerable systems, automatically flexiblesurgical systems, remotely flexible surgical systems, remotelyarticulating surgical systems, wireless surgical systems, modular orselectively configurable remotely operated surgical systems, etc.

The robotic surgical systems may be employed with one or more consolesthat are next to the operating theater or located in a remote location.In this instance, one team of clinicians may prep the patient forsurgery and configure the robotic surgical system with one or more ofthe instruments disclosed herein while another clinician (or group ofclinicians) remotely controls the instruments via the robotic surgicalsystem. As can be appreciated, a highly skilled clinician may performmultiple operations in multiple locations without leaving his/her remoteconsole which can be both economically advantageous and a benefit to thepatient or a series of patients.

For a detailed description of exemplary medical work stations and/orcomponents thereof, reference may be made to U.S. Patent ApplicationPublication No. 2012/0116416, and PCT Application Publication No.WO2016/025132, the entire contents of each of which are incorporated byreference herein.

Persons skilled in the art will understand that the structures andmethods specifically described herein and shown in the accompanyingfigures are non-limiting exemplary embodiments, and that thedescription, disclosure, and figures should be construed merely asexemplary of particular embodiments. It is to be understood, therefore,that the present disclosure is not limited to the precise embodimentsdescribed, and that various other changes and modifications may beeffected by one skilled in the art without departing from the scope orspirit of the disclosure. Additionally, the elements and features shownor described in connection with certain embodiments may be combined withthe elements and features of certain other embodiments without departingfrom the scope of the present disclosure, and that such modificationsand variations are also included within the scope of the presentdisclosure. Accordingly, the subject matter of the present disclosure isnot limited by what has been particularly shown and described.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed is:
 1. A surgical instrument, comprising: a housingincluding at least one actuator disposed thereon; an elongated shaftextending from a distal portion of the housing, the elongated shaftincluding an end effector assembly engaged at a distal end thereof, theend effector assembly including a pair of opposing jaw members, at leastone of the jaw members including a knife channel defined therein; anarticulation section disposed between the housing and the end effectorassembly, the articulating section configured to selectively articulatethe end effector assembly upon actuation of the at least one actuator,the articulating section and a proximal end of the knife channeldefining a first distance therebetween; and a knife assembly including:a knife having proximal and distal ends defining a knife lengththerebetween, the proximal end including an engagement feature disposedthereon; and a knife drive rod configured to operably engage theengagement feature to secure the knife drive rod to the knife such thatthe distal end of the knife extends beyond the engagement feature andwherein the knife length is less than the length of the first distance.2. The surgical instrument according to claim 1, wherein the engagementfeature of the knife assembly includes at least one capture tab disposedwithin in an aperture defined within the proximal end of the knife. 3.The surgical instrument according to claim 2, wherein the knife assemblyfurther comprises: a tube configured to operably engage the at least onecapture tab disposed within the aperture; and a knife drive rodconfigured to operably engage the tube disposed within the aperture. 4.The surgical instrument according to claim 3, wherein a weld operablyengages the tube to the knife.
 5. The surgical instrument according toclaim 6, wherein the knife and the tube are made from similar metals toincrease the strength of the weld.
 6. The surgical instrument accordingto claim 1, wherein the distal end of the knife drive rod threadablyengages the tube.
 7. The surgical instrument according to claim 1,wherein the engagement feature includes an aperture defined within theknife, the aperture configured to receive a bent end of the knife driverod.
 8. The surgical instrument according to claim 1, wherein theengagement feature of the knife includes an aperture defined in theproximal end that includes a series of spaced apart fins extendingthereacross and the knife drive rod is configured to operably engage thefins to secure the knife drive rod to the knife.
 9. The surgicalinstrument according to claim 1, wherein a retention mechanism isoperably disposed at a distal end of the knife drive rod and isconfigured to secure the knife drive rod in engagement between the fins.10. The surgical instrument according to claim 8, wherein the knifedrive rod is configured to engage the fins in a weave-like manner from aproximal end of the aperture to a distal end of the aperture.
 11. Thesurgical instrument according to claim 1, wherein the engagement featureincludes at least one detent disposed on a proximal end of the knife andthe knife drive rod includes at least one complementary aperture definedtherein configured to engage the at least one detent to secure the knifeto the knife drive rod.
 12. The surgical instrument according to claim11 wherein the at least one detent is spot welded within the aperture.13. A surgical instrument, comprising: a housing including at least oneactuator disposed thereon; an elongated shaft extending from a distalportion of the housing, the elongated shaft including an end effectorassembly engaged at a distal end thereof, the end effector assemblyincluding a pair of opposing jaw members, at least one of the jawmembers including a knife channel defined therein; an articulationsection disposed between the housing and the end effector assembly, thearticulating section configured to selectively articulate the endeffector assembly upon actuation of the at least one actuator, thearticulating section and a proximal end of the knife channel defining afirst distance therebetween; and a knife assembly including: a knifehaving proximal and distal ends defining a knife length therebetweenthat is less than the length of the first distance; and a knife driverod welded to the knife.
 14. The surgical instrument according to claim13, wherein the weld formed between the knife and the knife drive rod isdisposed on a proximal end of the knife.
 15. The surgical instrumentaccording to claim 13, wherein the weld formed between the knife and theknife drive rod is disposed along an inner surface of the knife.